1. Field of the Invention
This invention relates to the use of waste materials produced by coal-fired equipment to produce useful products. Specifically, the invention provides solid bricks produced by a process utilizing fly ash, bottom ash, and other components. Further, the solid bricks may be used to encapsulate waste materials and, if necessary, may be coated with an impermeable synthetic polymer film.
2. Description of the Related Art
There are currently a large number of coal-fired power plants operating in the United States. At normal levels of production, these power plants annually produce millions of tons of fly ash and bottom ash, the residual waste product produced by burning coal. Because these waste products contain heavy metal elements and potentially harmful chemical elements, they pose a disposal problem and also require fairly expensive material handling procedures and equipment.
The disposal expenses and problems posed by both fly ash and bottom ash are further compounded by the ever decreasing availability of landfills for disposal of these waste materials. Further, this method of disposal also presents problems because of the solubilization of contaminants and heavy metals in these ashes that can leach from the waste and contaminate underground aquifers, which are frequently a source of water supply for municipalities and farms.
At the same time, the growth of the oil and chemical industry has lead to a tremendous increase in the production of waste byproducts from oil refining and chemical processes. These waste byproducts must be disposed of in an environmentally responsible manner. Typically, these wastes are disposed of in hazardous waste landfills, at great expense. The wastes, if liquid, are typically placed in drums which are then placed in the storage site. This method of disposal is contentious because it is asserted that these drums cannot provide permanent containment of the waste but will deteriorate over a period of time so that leakages will inevitably result. These leakages of hazardous material could then seep into the soil ultimately reaching and contaminating underground aquifers that are a source of potable water.
Concurrently, there is also a need in the United States for inexpensive housing. This need has arisen due to the gradual but inexorable growth in population and the increasing cost of land in and around the major cities of the United States. This problem is clearly in a technology sense unrelated to the problems posed by wastes generated from coal-fired power plants and the wastes generated from oil and chemical industrial processes. However, it would be desirable to find a solution that encompasses all of these problem areas.